The latest report on open-source textbooks estimates that college students could save, on average, $128 per course.

The report, released in 2015 by the Student Public Interest Research Groups, analyzed results from five colleges. Although the statistical sample was very low, the group boasts previous research in the subject area and points to a wealth of data from other sources, notably the College Board, that illustrates the high cost of college textbooks and a corresponding reluctance of many students to spend money on textbooks at the expense of other essentials like room and board.

The open-source textbook initiative got a powerful ally in the California State Government, which allocated funding in 2012 for dozens of open-source digital textbooks and an online library to store the books. Other states, Utah and Florida and Minnesota among them, are considering similar efforts at the highest levels of state government.

Universities across the country have followed suit.

The College Open Textbooks (COT) Collaborative is a consortium of colleges, non-profits, and governmental agencies from across the country. States represented include California, Florida, New York, Pennsylvania, Texas, and Washington.